David Tennant's Tenth Doctor experiences his own timeline in a (mostly) linear fashion, but it can be a complicated thing for viewers at times.

Donna Noble, Martha Jones, and, of course, the Tenth Doctor. This episode is a true celebration of David Tennant's tenure as the Tenth Doctor, which wouldn't be complete without Rose Tyler.

From runaway bride to galactic traveller ... and the Doctor are an item! With Michelle Ryan. David's video diary from Dubai. Facts and figures from Captain Jack. How scary is the episode?